Kevin Costner Explores the Origins of Yellowstone in Fox Nation Docuseries: 'I Want to See What They Saw'

Kevin Costner stars as Montana rancher John Dutton in the TV series Yellowstone, but his passion for the national park — and its incredible history — runs far beyond his role on screen.

The Oscar winner explores the beauty, wildlife and origin of Yellowstone National Park in honor of its 150th anniversary for his new Fox Nation docuseries Yellowstone One-Fifty, which he says was inspired after he learned how the park came to be back in 1872.

"We take a lot for granted, but because people risked a lot, we all have much richer lives," Costner, 67, tells PEOPLE in this week's issue. "Contributing my time towards the story seeing more light of day is just a tiny thing."

In the four hour-long episodes, Costner retraces the steps of American geologist Ferdinand Vandeveer Hayden, whose 1871 expedition resulted in the creation of Yellowstone, the world's first national park.

"This was a time in America when all people cared about was what they could extract from the land, what they could get out of it," Costner explains in the doc's premiere episode. "But these pioneers, they came up with an entirely new idea — a new way of finding value in the land. I want to see what they saw. I want to see what changed them."

Now, a century and a half later, there are more than 4,000 parks worldwide, encompassing more than 2 million miles of pristine nature that are protected from destruction.

Costner explains that without Hayden's unprecedented vision for preservation, the park never would have been created.

"Congress commissioned Ferdinand Hayden to go investigate Yellowstone. He recruited some of the best geologists, cartographers and zoologists in the world. He also brought along a photographer and a painter to document their findings and the 32 men headed west," Costner says.

"Their mission was two-fold: The search for mineral exploits that could benefit the American people and to find a path that could build a railroad that would connect the Mississippi River to the Pacific Ocean," he explains.

"They weren't here to protect Yellowstone, they were here to tear it to shreds in the name of progress. But something happened during their three-month journey," he continues. "This place, it did something to them — and slowly but surely started to change their minds. And that's why it's still here. She's still here."

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Yellowstone: One Fifty with Kevin Costner streams Sunday exclusively on Fox Nation.